Cardiac Troponin-T as a Marker of Myocardial Dysfunction in Term Neonates with Perinatal Asphyxia: Correspondence

Excerpt

To the Editor: We have read with interest the paper by Joseph S et al. [1] about Troponin-T in perinatal asphyxia as a marker of myocardial injury. However, it is necessary to discuss aspects related to the real importance of this marker. Perinatal asphyxia can compromise many organs, such as kidney, liver, heart and brain, secondary to ischemic-hypoxic lesions. These lesions will increase ureic nitrogen, creatinine, hepatic and cardiac enzymes, the increase being directly proportional to the severity of the hypoxic injury. The above applies to specific markers of organs such as troponin T, a marker of myocardial damage severity. But the problem can be more serious if there is hemodynamic compromise, such as hypotension (shock), which would increase brain damage. Authors suggest that the increase of the troponin T early, could predict the need of intervention, besides being a prognostic marker. However, certain clinical signs such as bradycardia, capillary filling time, cardiac murmur, distal cold and finally hypotension are clear indicators of intervention, such as vasoactive support in cases of myocardial dysfunction. The management will be adjusted to the clinical condition, and not to the levels of troponin T. On the other hand, troponin levels show higher values due to the presence of cardiorespiratory compromise associated with adaptation post-natal, which is not always secondary to hypoxia [2]. Diagnosis must be well established, for immediate management and eventual long-term sequelae. Within the diagnostic criteria used in the research, the highest pH in relation to defined criteria of asphyxia, besides not referring the base deficit within the criteria, constitutes very important prognostic markers in asphyxiated neonates [3]. One should be careful with the use of troponin T, as an alternative in hospitals without availability of echocardiogram, because other clinical conditions can elevate troponin T levels, such as congenital heart disease and respiratory distress [1,2] and the echocardiogram is a necessary test in case of perinatal asphyxia, especially in moderate to severe cases and differential diagnoses [4]. …